Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 260632
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
132 AM EST MON JAN 26 2015

.SYNOPSIS...
LOW PRESSURE OVER THE LOWER OHIO VALLEY WILL WEAKEN ACROSS THE
SOUTHERN APPALACHIANS LATER TONIGHT INTO MONDAY MORNING. A NEW LOW
PRESSURE SYSTEM WILL DEVELOP OFF THE COASTAL CAROLINAS MONDAY
MORNING...AND RAPIDLY INTENSIFY OFF THE MID ATLANTIC COAST MONDAY
NIGHT. THE LOW WILL CONTINUE TO PULL OFF TO THE NORTHEAST OF THE
AREA THROUGH TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CURRENT GOES WV IMAGERY THIS EVENING INDICATES A RATHER DYNAMIC
MID/UPPER SYSTEM TRACKING ACROSS KY/TN...WITH THE UPPER PV MAX
DIVING ACROSS THE LOWER MISSISSIPPI VALLEY. THIS SYSTEM EVEN
GENERATED THUNDERSTORMS OVER AL EARLIER THIS EVENING. A QUIET
EVENING IS OCCURRING LOCALLY WITH JUST A SLOW INCREASE IN CLOUDS AS
THE SYSTEM IS SLOW TO ADVANCE E. THE LATEST HIGH RES DATA (RAP/HRRR)
ALONG WITH THE 26/00Z NAM SUGGEST DEEP LIFT/UVM ASSOCIATED WITH THE
SYSTEM REACHES THE ERN VA PIEDMONT AROUND 09-15Z. IT THEN WEAKENS
FROM 15-18Z AS THE MAIN ENERGY TRANSFERS TO THE DEVELOPING SFC LOW
OFF THE COASTAL CAROLINAS. GIVEN THIS...LIKELY POPS WILL BE FORECAST
MAINLY W OF I-95 LATE TONIGHT INTO MONDAY MORNING...BEFORE
TRANSITIONING TO FAR NRN PORTIONS THROUGH THE REMAINDER OF THE DAY.
THE LATEST DATA DOES SUGGEST HIGHER QPF WITH THE INITIAL RAIN LATE
TONIGHT/MONDAY MORNING...BUT STILL AMOUNTS SHOULD BE 0.30" OR LESS.
LOWS IN THE MID-UPPER 30S /ABOVE FREEZING ALL AREAS SO NO P-TYPE
CONCERNS OVERNIGHT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
A WINTER STORM WATCH REMAINS IN EFFECT FOR THE MD ERN SHORE MON
NIGHT INTO TUE...

FAVORING A BLEND OF THE 12Z NAM/ECMWF AND 15Z SREF THIS
PERIOD. HAVE NOTED 12Z GFS HAS A SPURIOUS LOOKING BULLSEYE OF QPF
OVER PORTIONS OF THE CWA WEST OF THE BAY MON NIGHT/EARLY TUE. THE
06Z GFS HAD THIS AS WELL (ALTHOUGH A BIT FARTHER TO THE SOUTH). OF
NOTE...THE 26/00Z NAM AS WELL AS THE 25/18Z GFS BOTH INDICATE A
SECONDARY ZONE OF DEFORMATION AND BAND OF FRONTOGENESIS BACK OVER
CENTRAL VA MONDAY NIGHT...WHICH HAS COULD COMPLICATE THE SNOW
FORECAST.

FOR MON...THE ENERGY WILL CONTINUE TO TRANSFER TO THE OFFSHORE SFC
LOW AND MUCH OF THE AKQ CWA WILL BE IN SORT OF A LULL WITH FAIRLY
WEAK LIFT DESPITE MAINLY CLOUDY SKIES. STILL HAVE LIKELY POPS ACRS
THE NORTH AND CHC POPS SOUTH ON MON...JUST DO NOT EXPECT MUCH IN
THE WAY OF QPF. HIGH TEMPERATURES HAVE BEEN RAISED A FEW MORE DEGREES
FROM PREVIOUS FORECAST...INTO THE MID 50S IN NE NC...TO THE LOWER
40S OVER THE FAR NORTHERN TIER. WE WENT CLOSER TO THE MET NUMBERS
DUE TO A LACK OF FAITH IN THE GFS MODEL THIS CYCLE.

THE MAIN EVENT FOR OUR AREA BEGINS MON NIGHT...AS COLDER AIR
PLUNGES SOUTH IN RESPONSE TO RAPID INTENSIFICATION OF THE SFC LOW
OFF THE VA COAST. STILL MAINLY RAIN ACRS THE SOUTHERN 2/3 OF THE
CWA IN THE EVENING...BECOMING ALL SNOW BETWEEN 03-06Z FOR MOST
LOCATIONS. DURING THIS TIME...BEST LIFT/FRONTOGENESIS WILL RESIDE
OFF THE COAST. WILL BE RELYING ON DEFORMATION ZONE AND INTENSE
BANDING DEVELOPING FROM THE DELMARVA TO LOG ISLAND TO "WRAP
AROUND" AND DROP SOUTH FOR MOST OF OUR SNOW INTO THE DAY TUE.
THUS...SNOW AMOUNTS WILL SHOW A SHARP CUTOFF. ANY CHANGE IN
POSITION OF THIS BANDING CAN HAVE DRASTIC EFFECTS ON SNOW
AMOUNTS...SO UNCERTAINTY REMAINS RATHER HIGH. HAVE FORECAST
ROUGHLY 3-6" OF SNOW ON THE MD ERN SHORE IN THE WATCH AREA...WITH
2-3" ACRS NRN NECK/VA ERN SHORE (AREAS THAT WILL PROBABLY NEED AN
ADVISORY)...TAPERED FAIRLY QUICK TO < 1" OVER MOST OF THE REMAINDER OF
THE CWA. COULD SEE SLIGHTLY MORE THAN 1" ACRS HAMPTON ROADS EARLY
TUE HOWEVER.

SNOW IS EXPECTED TO TAPER OFF LATE TUE MORNING/AFTN...BUT IF ECMWF
IS CORRECT THIS WOULD BE SLOWER AND ADDITIONAL SNOW AMOUNTS MAY
NEED TO BE ADDED. MAV/MET GUIDANCE LOOKS TOO WARM TUE...ESPECIALLY
ACRS THE NE. EXPECT HIGHS IN THE LWR 30S NE TO AROUND 40 F SW.
CLEARING/COLD TUE NIGHT/WED WITH LOWS IN THE UPPER TEENS TO MID
20S AND HIGHS ON WED IN LWR 40S SW TO THE LWR 30S NE.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE BLO NORMAL TEMPS WITH DRY WX MOST
DAYS. FOR WED NIGHT...SFC HI PRES BLDS OVR THE MID ATLANTIC AND SE
STATES AS THE NEXT LO PRES SYSTM APPROACHES FM THE W. WITH A MSTLY
CLEAR SKY AND LIGHT WINDS...TEMPS WILL FALL INTO THE MID 20S IN MOST
SPOTS. LO PRES AND AN ASSOCIATED MID-LEVEL VORT MAX WILL BRING
PRECIP (PLAIN RAIN) INTO THE AREA STARTING LATE THU. FAVORED THE
SLIGHTLY SLOWER ECMWF SOLUTION...WITH A 30% CHANCE OF PRECIP (RA/SN
NORTH AND RA SOUTH) THU NIGHT...WITH LO TEMPS IN THE LO TO MID 30S.
CONDS THEN DRY OUT INTO FRI AND SAT AS SFC HI PRES BLDS IN FM THE W.
EXPECT A PRTLY CLOUDY SKY BOTH DAYS WITH NW WINDS AND HI TEMPS
FALLING FM THE 40S ON FRI TO THE MID 30S TO LWR 40S ON SAT.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...

AS OF 06Z...VFR CONDITIONS ACROSS AREA TERMINALS WILL CONTINUE
INTO MONDAY MORNING. MID AND HIGH LEVEL CLOUDS SLOWLY INCREASE
OVER THE NEXT FEW HOURS, WITH CLOUD BASES LOWERING LATER THIS
MORNING...FIRST OVER RIC/SBY THROUGH 15Z...THEN BY LATE
MORNING/AFTN OVER PHF/ORF/ECG. LIGHT RAIN IS FORECAST TO DEVELOP
MAINLY AT RIC THIS MORNING...WITH VCSH WORDING AT SBY BY LATE
MORNING. BLENDED CURRENT POPS WITH SOME OF THE GUIDANCE FOR
STARTING TIMES OF PCPN. CIGS AND VSBYS LOWER TO MVFR AND IN SOME
CASES IFR DURING THE AFTN EXCEPT AT ECG. THE LOWEST CONDITIONS FOR
THIS TAF PERIOD AND BEYOND APPEAR TO BE LINING UP FOR SBY WHERE NE
WINDS WILL ALSO BECOME GUSTY.

OUTLOOK...RAIN CHANGES TO SNOW DURING THE LATE EVENING HOURS
MONDAY INTO EARLY MORNING HOURS OF TUESDAY (02-06Z/TUESDAY) AND
CONTINUES TROUGH MIDDAY TUESDAY. SNOW MAY BE HEAVY AT TIMES AT
SBY THROUGH TUESDAY MORNING WHERE ACCUMULATING SNOWFALLIS
CURRENTLY FORECAST. ELSEWHERE, A LIGHT ACCUMULATION OF SNOWFALL IS
EXPECTED AT RIC/PHF/ORF WITH ONLY A TRACE AMTS OF SNOW EXPECTED AT
ECG. IFR CONDITIONS ARE EXPECTED BY LATE AFTN AND THROUGH THE
EVENING AT SBY AND WL CONTINUE OVERNIGHT MON ESPECIALLY DURING
PERIODS OF ACCUMULATING SNOW. IFR CONDS WILL BE POSSIBLE MONDAY
NIGHT AT PHF/ORF/ECG, MAINLY TOWARDS THE END OF THE TAF PERIOD AND
INTO TUESDAY MORNING.

DRY AND MAINLY VFR CONDS ARE EXPECTED DURING THE REST OF THE WEEK.
THERE WILL BE A CHC FOR PCPN LATE IN THE WEEK MAINLY ON THURSDAY
NIGHT.

&&

.MARINE...
HEADLINES HAVE BEEN HOISTED OVR ALL WTRS FOR THE UPCOMING STRONG
CSTL LO. FOR TNGT...10-15 KT SE WINDS WILL SLOWLY SHIFT TO THE E AS
SFC LO PRES APPROACHES FM THE W. THE LO WILL REDEVELOP OFF THE
CAROLINA CST ON MON...AND STRENGTHEN AS IT SLOWLY ADVANCES NEWRD
INTO MON NIGHT. A GALE WARNG HAS BEEN ISSUED FOR CSTL WTRS N OF
PARRAMORE ISLAND WHERE CONFIDENCE FOR 34+ KT WINDS IS HI ON THE BACK
SIDE OF THE LO. FOR THE REMAINDER CSTL WTRS AND THE BAY...WITH THIS
BEING 3RD PERIOD AND STILL SOME UNCERTAINTY...WENT AHEAD WITH A GALE
WATCH FOR NOW AND WILL BE CONVERTED TO EITHER A GALE WARNG OR SCA IN
FUTURE UPDATES. OTWS...WENT WITH A SCA FOR THE SOUND AND RIVERS.
ANOTHER THING OF NOTE IS SEAS WITH THIS EVENT...EXPECTED TO RISE TO
AT LEAST 12 FT OUT 20NM OVR NRN CSTL WTRS. WAVES OVR THE BAY UP TO
5-6 FT. NW FLOW AND MARGINAL SCA CONDS MAY CONTINUE INTO TUE
NIGHT/WED AS SFC HI PRES SLOWLY BLDS IN FM THE W. SUB-SCA CONDS THEN
FOR WED NIGHT/THU.

&&

.TIDES/COASTAL FLOODING...
LOW PRESSURE INTENSIFIES RAPIDLY OFF THE MID-ATLANTIC COAST
MONDAY NIGHT/TUESDAY. THE RESULT WILL BE A PERIOD OF STRONG NLY
WINDS OVER THE WATERS. TIDAL ANOMALIES ARE EXPECTED TO REACH 1 TO
1.5 FT...POSSIBLY HIGHER...DURING MONDAY NIGHT AND TUESDAY
MORNINGS HIGH TIDE CYCLES. SITES IN THE LOWER BAY WILL REACH
HIGHEST ASTRO TIDE WITH WATER LEVELS APPROACHING MINOR FLOODING
THRESHOLDS AT SEWELLS POINT MONDAY NIGHT. FOR OCEAN CITY...MINOR
FLOODING IS EXPECTED WITH A SMALL CHANCE FOR MODERATE AS
WELL...BUT NOT HIGH ENUF LIKELIHOOD TO ISSUE ANY WATCH/WARNING ATTM
WITH THIS STILL THREE HIGH TIDE CYCLES OUT. WILL RE-EVALUATE TNGT.
HIGH ANOMALIES ARE EXPECTED AGAIN TUES...BEFORE ANOMALIES DROP OFF
LATE TUES INTO TUES NIGHT AS THE LOW LIFTS AWAY FROM THE REGION.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WATCH FROM THIS EVENING THROUGH TUESDAY AFTERNOON
     FOR MDZ021>025.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ635>638.
     GALE WATCH FROM THIS EVENING THROUGH TUESDAY EVENING FOR
     ANZ630>632-634.
     SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 4 AM EST
     WEDNESDAY FOR ANZ633.
     GALE WATCH FROM THIS EVENING THROUGH TUESDAY EVENING FOR
     ANZ654-656-658.
     GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 PM EST TUESDAY FOR
     ANZ650-652.

&&

$$
SYNOPSIS...LKB
NEAR TERM...AJZ/LKB
SHORT TERM...AJZ/LKB
LONG TERM...MAS
AVIATION...MAM/LSA
MARINE...MAS
TIDES/COASTAL FLOODING...





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